New research suggests a robust vocabulary may reduce mild cognitive impairment and lead to a lower risk of developing dementia.
Mild cognitive impairment (MCI) or incipient dementia is a condition that some people develop as they age. Many experts believe it is an intermediate state between normal cognition and dementia.
MCI is defined as cognitive decline greater than expected for an individual’s age and education level but that does not interfere notably with activities of daily life. Symptoms often include forgetfulness and a decline in executive skills.
Researchers from the University of Santiago de Compostela in Spain studied the way in which the brain compensates for cognitive impairment and discovered the brain uses its cognitive reserve to make up for memory loss.
“Cognitive reserve” is the name given to the brain’s capacity to compensate for the loss of its functions. This reserve cannot be measured directly; rather, it is calculated through indicators believed to increase this capacity.
Scientists discovered use of a higher level of vocabulary appears to buttress cognitive reserve.
As Cristina Lojo Seoane, co-author of the study published in the journal Anales de Psicología (Annals of Psychology), said, “We focused on level of vocabulary as it is considered an indicator of crystallized intelligence (the use of previously acquired intellectual skills). We aimed to deepen our understanding of its relation to cognitive reserve.”
Investigators chose a sample of 326 subjects over the age of 50. Two hundred twenty two were healthy individuals and 104 presented mild cognitive impairment.
Researchers then measured subjects levels of vocabulary, along with other measures such as their years of schooling, the complexity of their jobs, and their reading habits.
They also analyzed the scores they obtained in various tests, such as the vocabulary subtest of the Wechsler Adult Intelligence Scale (WAIS) and the Peabody Picture Vocabulary Test.
“With a regression analysis we calculated the probability of impairment to the vocabulary levels of the participants,” Lojo Seoane said.
The results revealed a greater prevalence of mild cognitive impairment in participants who achieved a lower vocabulary level score.
“This led us to the conclusion that a higher level of vocabulary, as a measure of cognitive reserve, can protect against cognitive impairment,” Lojo Seoane said.